1. Field of the Invention
The present disclosure relates to a polyimide fiber and a method for producing a polyimide fiber.
2. Description of the Related Art
Polyimide has excellent characteristics in terms of heat resistance, chemical resistance, mechanical properties, electric properties and the like, and thus is widely used in the fields of electronic components, batteries, automobiles, aerospace industry and the like.
As an example in which polyimide having such characteristics is used, it is sought to use polyimide for a fiber material of fiber reinforced plastic (FRP). In order to achieve this purpose, it is desired to produce polyimide fibers having an adequate strength. Various methods for producing polyimide fibers have so far been proposed (for example, see Japanese Patent Application Laid-open Nos. S60-65112 and 2010-180494).
Japanese Patent Application Laid-open No. S60-65112 discloses preparing a dope solution by dissolving a soluble powder polyimide in a phenolic solvent and forming the dope solution into a shape of fiber by wet spinning.
Japanese Patent Application Laid-open No. 2010-180494 discloses a method for producing a polyimide fiber by solution spinning using a solution of soluble polyimide in an aprotic polar organic solvent.